Auto feeders aren't any more reliable than having someone else take care of your tank. Fish can easily go a couple of weeks without food.
Here's what you do: A couple of weeks before you leave, feed the fish a little more and a little more often. A couple of days prior to leaving, stop feeding and do a bit larger water change. Your fish will be fine while you're gone and won't need to be fed. You'll come home to a clean tank and you can start up your regular tank routine.
"Fear not, my young apprentice. Just change the tank water."